Swivel arrangement



Sept 7, 1955 B. s. SILVER SWIVEL ARRANGEMENT Filed March 20, 1964 2 Sheets-Sheet l m l l INVENTOR f//ffffz//f ATTORNE;

SePt- 7, 1955 B. s. SILVER 3,204,915

SWIVEL ARRANGEMENT Filed March 20, 1964 2 Sneeizs-SheeiI 2 T'lCIrf5 20 /9 l a l y Uhm! Z. \\\\v.\\\\\\\\\\\"\\\\\ y? BY mama-Ld EV ORN 5' ATT United States Patent O 3,204,915 SWIVEL ARRANGEMENT Bertram S. Silver, '565 Park Ave., New York 21, N.Y. Filed Mar. 20, 1964, Ser. No. 353,553 10 Claims. (Cl. 24S-417) The present invention relates generally to improvements -in furniture and it relates in particular to an improved swivel chair which is biased to predetermined positions.

Under many conditions, such as for office and other uses, it is frequently desirable to employ a swivel type of chair. However, although the swivel type of seat should be easily turnable, where it is freely rotatable and has no predetermined equilibrium positions to which it is normally biased, such chair structure possesses many undesirable features. Numerous mechanisms have been employed and suggested for urging the seat of a swivel chair to predetermined positions but these have had only limited applications, being often complicated and awkward devices, unreliable, expensive, subject to frequent malfunctioning and otherwise leaving much to be desired.

It is thus a principal object of the present invention to provide an improved article of furniture.

Another object of the present invention is to provide an improved swivel chair.

Still another object of the present invention is to provide an improved swivel chair in which the seat is normally resiliently biased to preselected positions.

A further object of the present invention is to provide an improved, highly compact biasing mechanism for swivel chairs and the like.

Still a further object of the present invention is to provide a swivel chair mechanism of the above nature characterized by its ruggedness, simplicity, adaptability and reliability.

The above and other objects ofthe present invention will become apparent from a reading of the following description, taken in conjunction with the accompanying drawings, wherein FIGURE 1 is a front perspective view of a swivel chair embodying the present invention, being illustrated by broken line in a reverse equilibrium position;

FIGURE 2 is a horizontal sectional View taken along line 2 2 in FIGURE 4 of the seat biasing mechanism illustrated in an equilibrium position;

FIGURE 3 is a fragmentary sectional view similar t0 FIGURE 2, the biasing mechanism being illustrated intermediate its opposite equilibrium positions;

FIGURE 4 is a sectional view taken along line 4-4 in FIGURE 2,

FIGURE 5 is an enlarged sectional view taken along line 55 in FIGURE 3; and

FIGURE 6 is an exploded perspective view of the seat biasing mechanism.

In a sense, the present invention contemplates the provision of a swivel chair comprising a support member, a seat member mounted atop said support member and rotatable about a vertical axis, and a biasing mechanism intercoupling said seat and support members and including a cam mounted on one of said members and limited to a transversely sliding movement and having a cam surface extending eccentrically relative to said vertical axis and a cam follower mounted on the other of said members and engaging said cam surface, and spring means urging said cam follower and said cam toward each other.

According to a preferred form of the improved swivel chair, the support member comprises an upright column atop which the seat member is journalled. The biasing mechanism includes a rectangular housing disposed below the seat member and affixed to the column and having a 3,2%,9l5 Patented Sept. 7, 1965 ice horizontally extending bottom wall, upstanding laterally spaced side walls and longitudinally spaced end walls. A pair of longitudinally spaced laterally extending cam members are nested in the housing and have side faces engaging the housing side walls to limit the cam members to longitudinal sliding movement, and confronting cam surfaces. Each ofthe cam surfaces is delineated by a pair of side-by-side concave cylindrical surfaces converging to a cusp between the ends yof the cam surface, the cusps of the cam surfaces. preferably being relatively laterally olfset. The cam members have laterally spaced pairs of aligned longitudinal bores formed therein which are slidably engaged by longitudinal rods and the cams are urge toward each other by helical compression springs registering with the rods and entrapped between the housing end Walls and the end faces of the respective confronting cam members. The cam followers are supported by axles depending from and aiiixed to the underface of the seat member and engage respective of the cam surfaces.

Referring now to the drawings, which illustrate a preferred embodiment of the present invention, reference numeral 10 generally designates the improved swivel chair which has a pair of opposite equilibrium positions and which includes a support member 11 atop which is mounted a swivel seat member 12 rotatable about a vertical axis. Support member 11 comprises an upright vertical cylindrical column 13 provided with radially outwardly directed longitudinal vertical flanges or ribs 14 each of which terminates in a coplanar downwardly outwardly inclined leg 16, the group of four legs, as illustrated defining a support spider. A suitable foot piece or caster 17 is disposed within and depends from the free end of each of legs 16. Located atop column 13 and ribs 14 and formed integral therewith or otherwise aiixed thereto is a flat circular platform 18. A cylindrical vertical shaft 19 is directed upwardly from platform 18 and is coaxial with column 13 and platform 18. Shaft 19 is provided with a peripheral groove 20 formed in its surface a short distance below the top thereof.

A rectangular housing 21 is mounted atop circular platform 18 and includes a horizontal tioor portion 22 resting on platform 18 and affixed thereto by screws 23 registering with countersunk openings formed in oor 22 engaging corresponding tapped vertical bores formed in platform 18 and ribs 14, the top of the screw heads being coplanar with, or sunk below, the upper face of floor 22. A central circular opening 24, coaxial with and of somewhat greater diameter than shaft 19, is formed in floor 22. Directed upwardly from the edges of floor 22 are laterally spaced vertical side walls 26 and longitudinally spaced vertical end walls 27.

Nested in housing 21 and longitudinally slidable therein are a pair of opposing block shaped cam members 28 having flat bottom faces resting on oor portion 22 and iiat top faces at substantially the level of the top edges of housing side and end walls 26 and 27. Each of cam members 23 includes longitudinally extending side faces 29 which slidably engage corresponding housing side walls 25 and an outer laterally extending end face 30 which confronts a corresponding housing end wall 27.

'Ihe confronting faces of cam members 28 have formed therein cam surfaces 32, each of which is delineated by a pair of side-by-side concave cyindrical surfaces 33 eccentric to shaft 19, the adjacent sections of the cylindrical surfaces 33 converging to an inwardly directed cusp 34. It should be noted that the cusps 34 of the respective cam surfaces 32 are advantageously slightly laterally offset in opposite directions relative to the axis of shaft 19. Formed in each cam member 28 is a pair of laterally spaced aligned longitudinal bores 28a disposed laterally outside cam surfaces 32 and slidably engaged by longitudi- 3 nally extending rods 36 which extend between the housing end walls 27.

Cam members 28 are resiliently urged toward each other by a plurality of helical compression springs 37 which register with the opposite ends of each of rods 36 and are entrapped between end walls 27 of the housing and the respective end faces 30 of the confronting cam members. A cover plate 38 overlies the housing 21 and the cam members 28 and is provided with depending side skirts 39 which abut the outer faces of the housing side walls 26 and are secured thereto by screws 40. A large circular opening 41 is centrally located in the cover plate 38.

Seat member may be of any desirable construction and includes a seat section 41a and a back rest section 42 upwardly rearwardly directed from the rear of seat section 41, Seat section 41 :includes a base plate 43 having a central aperture formed therein which is engaged by a vertical sleeve 44 projecting above and below the base plate 43 and aixed thereto as by welding or the like. A bushing 46 registers with the shaft 19 and has a lower end 47 of enlarged cross-section registering with the aperture 24 and resting on platform 1S, provided with an upwardly facing peripheral shoulder and having an upper end at the level of shaft groove 20. Sleeve 44 is telescoped by bushing 46 and rests on the shoulder of bushing section 47, the upper ends of sleeve 44 and bushing 46 being coplanar. A split ring 48 registers with the groove 20 and bears on the upper ends of the bushing 46 and sleeve 44 to effect a locked relatively rotatable assembly.

A pair of vertical pins 49 are aixed to and depend from base plate 43 of seat 41 and are disposed at diametrically opposite positions relative to and spaced from sleeve 44, pins 49 terminating at their lower ends in enlarged flat heads 50. A cam follower-defining roller 51 engages each pin 49, resting on a corresponding head 50 and located between the confronting cam surfaces 32, and is maintained in position on the pin 49 by a spacer collar 52 registering with the pin 49 and disposed between seat base plate 43 and the respective roller 51.

Considering now the operation of the swivel chair 10 as described above, seat member 12 normally assumes a forwardly or rearwardly facing orientation with the cam followers 51 disposed between and abutting the respective opposing end faces of cam surfaces 32. Seat member 12 and cam followers 51 are urged to this position by reason of the springs 37 bearing on the cam members 28 to urge them toward each other, the cam surface 32 in turn bearing on the cam followers 51 to swing them to their aforesaid equilibrium positions. Upon the turning of the seat member from its equilibrium position, the correspondingly displaced cam followers 51 bear on cam surfaces 32 to spread said cam members 23 and thereby to load the compression springs 37. If seat member 12 is swung less than 90 and then released, the cam followers will not move past cusps 34 and cams 28 will act upon the cam followers 51 to return them and the seat member to their original equilibrium positions. If, on the other hand, seat member 10 is swung more than 90 from its equilibrium position, and then released, cam followers 51 will advance past the cusps 34 and the contracting cam members 2S will effect the further advance of the cam followers 51. and rotation of the seat member 12 until they come to rest at their equilibrium positions diametricaily opposite the initial equilibrium positions.

It will be understood that the device of the present invention can be applied to other things than a chair, as, for example, a table, desk or the like. It will be understood, therefore, that the term chair as used in the claims is not to be limited merely to a seat and that it may encompass other articles, as the above, or cabinets, etc.

While there has been described and illustrated a preferred embodiment of the present invention, it is apparent that numerous alterations, omissions and additions may be made without departing from the spirit thereof.

I claim:

1. A swivel chair comprising a support member, a seat member mounted atop said support member and rotatable about a vertical axis, and a biasing mechanism intercoupling said seat and support members and including a pair of oppositely disposed cams mounted on one of said members and limited to a transversely sliding movement, each cam having a surface extending eccentrically relative to said vertical axis and a pair of cam followers mounted on the other of said members and respectively engaging said cam surfaces, and spring means urging said cam followers and said cams toward each other.

2. A swivel chair comprising a support member, a seat member mounted atop said support member and rotatable about a vertical axis, and a biasing mechanism intercoupling said seat and support members and including a pair of longitudinally spaced cams supported on one of sai-d members and restricted to longitudinally slidable movement toward and away from each other and having opposite cam surfaces extending eccentrically relative to said vertical axis and a pair of cam followers mounted on the other of said members and engaging corresponding of said cam surfaces, and spring means urging said cam followers and respective of said cams toward each other.

3. A swivel chair comprising a support column, a seat member mounted atop and journalled to said support column for rotation about a vertical axis, a horizontal cam guide underlying said seat member and aixed to said support column, a pair of opposite cam members engaging said cam guide and restricted thereby to longitudinal sliding movement toward and away from each other and having opposite cam surfaces eccentric to said vertical axis, a pair of cam followers aflxed to and depending from said seat member and radially oppositely disposed relative to said vertical axis and engaging respective of said cam surfaces, and spring means urging said cams toward respective of said cam followers.

4. A swivel chair comprising a support column, a seat member mounted atop and journalled to said support column for rotation about a vertical axis, a horizontal longitudinal cam guide underlying said seat member and aflixed to said support column, a pair of opposite cam members engaging said cam guide and restricted thereby to longitudinal sliding movement toward and away from each other and having confronting opposite cam surfaces eccentric to said vertical axis, a pair of cam followers affixed to and depending from said seat member and radially oppositely disposed relative to said vertical axis and engaging respective of said cam surfaces, and spring means urging said cams toward each other.

5. A swivel chair comprising a support column, a seat member mounted atopl and journalled to said support column for rotation about a vertical axis, a rectangular housing underlying said seat member and aixed to said column and including a horizontal bottom wall and upstanding laterally spaced side walls and longitudinally spaced end walls, a pair of opposite cam members nested in said housing on opposite sides of said vertical axis and having confronting cam surfaces eccentric to said vertical axis, and side walls slidably engaging said housing side walls to restrict said cams to longitudinal movement, spring means disposed between said housing end walls and the respective confronting faces of said cams to urge said cams toward each other, and a pair of diametrically opposed cam followers depending from said seat member and engaging respective of said cam surfaces.

6. The swivel chair of claim 5, wherein each of said cam surfaces is delineated by a pair of laterally spaced laterally extending concave surfaces converging to a cusp disposed between the lateral ends of said cam surface.

7. The swivel chair of claim 6, wherein said cusps are relatively laterally offset.

8. The swivel chair of claim 5, wherein said cam members have laterally spaced aligned, longitudinally extend- 5 5 ing bores formed therethrough and including rods slid- References Cited by the Examiner ably engaginf said aligned bores.

9. The sviivel chair of claim 8, wherein said spring UNITED STATES PATENTS means comprise helical compression springs registering 1,666,893 4/28 Gerrard 74-55 with said rods between said housing end walls and the 5 1,918,190 7/33 Miller etal 248-417 respective confronting faces of said cam members.

10. The swivel chair of claim 1, wherein the cam sur- CLAUDE A- LE ROY, Plmfy Exmlfleh faces are laterally offset with respect to each other. 

1. A SWIVEL CHAIR COMPRISING A SUPPORT MEMBER, A SEAT MEMBER MOUNTED ATOP SAID SUPPORT MEMBER AND ROTATABLE ABOUT A VERTICAL AXIS, AND A BIASING MECHANISM INTERCOUPLING SAID SEAT AND SUPPORT MEMBERS AND INCLUDING A PAIR OF OPPOSITELY DISPOSED CAMS MOUNTED ON ONE OF SAID MEMBERS AND LIMITED TO A TRANSVERSELY SLIDING MOVEMENT, EACH CAM HAVING A SURFACE EXTENDING ECCENTRICALLY RELATIVE TO SAID VERTIAL AXIS AND A PAIR OF CAM FOLLOWERS MOUNTED ON THE OTHER OF SAID MEMBERS AND RESPECTIVELY ENGAGING SAID CAM SURFACES, AND SPRING MEANS URGING SAID CAM FOLLOWERS AND SAID CAM TOWARD EACH OTHER. 